Elastic-fluid turbine.



o. G. mms. LASTIG FLUID TURBINE.

PPPPPP ATION FILED MAY 18, 1907.

, Patented Apr. 6, 1909. 2 SSSSSSSS HEET 1.

i@ Q A,

y lnated by the same reference characters.

' one whole stage and CHARLES G. cua-ris, or. Nsu/'Yoan N. Y., AssiGNoR, BY MESNE ASSIGNMENTS, To GENERAL `EL-ECTRIC COMPANY, A CORPORATIONOF NEW YQRK.

Entierro-FLUID merma.,

Specification of Letters Patent.

Patented April 6, 1909.

appnmm med nay 1s, 1901. serial No. 374,435.

Toall 'whom 'it may concern:

` Be it known that I, CHARLEs G; Cun'rls, a citizen of the UnitedStates, and a resident of the borough of Manhattan, city, county,- andState of New York, have invented an Improvement in Elastic-FluidTurbines, .of which the follom'ngs a specification. l

The object I have in view is to improve the eliciency of elastic fluidturbines and particularly to make them more eflicient when runningu-fithreduced loads and under less than full speed.

The invention is particularly adapted for steam turbines for marine use,and more especially in connection with vessels of war, yachts andvessels on special service Ind adapted to be run for a large proportionof the time they are under way at a reduced or cruising speed.

I attain these objects by the mechanism illustrated in the accompanyingdrawings, in

ch y, Figure 1 is a sectional view of a portion of a. turbine embodyingmy invention, and Figa. 2 is a development thereof.

In both ofthe views like parts are desig- The drawings illustrate onestage of 'a multi-stage turbine of the axial flow ty thc number ofstages 4used is immaterial, lit portions of two other stages areillustrated. l

In the drawings the moving buckets 1, 2, 3, are carried upon theperiphery 'ofthe wheel 4. The wheel turns within a shell ory casing 5.This shell is separated by diaphragme 6 6 into stages, there' being oneor more rows of moving buckets in each stage. The nozzles 7 are formedin the diaphragm 6 and direct the elastic iluid into the iirst row ofmoving Intermediate nozzles 8 and9 are iixed to the shell 5, and arearranged between the moving buckets 1 and 2, andn 2 and 3 respectively.The nozzles 7, 8 and 9 serve the twofold purpose of directing 'theelastic fluid' against the moving buckets and also of con-- verting aportion of the pressure of the lluid into velocity. r

I prefer in practice to arrange each rou' of moving buckets so as toabsorb an equal amount of energy, although this may be varied, ifdesired. The elastlc iluid, which may be steam or other after traversingthe rows'of moving buc bucket is provided for-the andnozzles, Will issueout of the last row of moving buckets 8,- and will be dischargedint-o'the next nozzle 7. The usual ractice is to provide a considerableinterva of space between the last row' of moving buckets 3 and the nextdiaphragm, so that the steam or other elasticlui'd employed mayhave anopportunity to expand to the pressure existing aint that the nextnbzzle,and from .there into the next wheel. v

By my invention I provide an opening 11 which is arranged so that itforms a passage-V way between the discharge from the buckets theentrance to the nozzle 7. This opening has a topwall 15 and a bottomwall 16. In the embodiment illustrated the walls are formed by anopening-made in a block 10.

This block 10 is referafbly attached to the dia hragm 6. 'l ecircumferential length of t e, opening is equal to the length of thenozzle 7, again`st`which it abuts, as 'is shown inFig. 2. The radialdepth ofthe opening 1 1 ,il preferably at its proximate end slightlygreater than the radial depth ofthe bucket 3. he excess of depth overthe depth. ofthe purpose of preventing an obstruction to the freedischarge 'of the fluid from the buckets 3. Theradial ldepth of the.ultimate end of the is that of the depth of the nozzles 7, against whichit abuts. The fixed nozzles may i11- crease in circumferential lengthtoward `the exhaust in order to pr'vrde for the increased volume o ffluid.

In order to prevent bstruction to the free passage of the iluid throughthe opening 11, the latter is made to increase in circumferential lengthin the direction of the exhaust,

stage before it'escapesthrough or transverse to the travel of the fluid.This increase in circumferential length of the passage may be made byinclining one ofthe walls 12. This incline is best made upon the curveshown in Fi 2, which I find to be substantially the pat that steamWill'take in discharging from buckets of the shape illustrated.

In order to prevent an objectionable expansion which would be caused bythe crosssectional area of the opening 11 increasing by the increase ofperipheral length, I prefer to have the .cross-sectional area or' theultimato gas or Huid under pressure, and proximate ends of the opening11 equal.

- his may be made by contracting the top los El()l .n open portion wildischarge ofthe moving buckets.

. opene and lbottom walls ofthe opening 11 at a ratio equal to thecontraction ofthe side Walls.

Inv order to prevent the escape of iuid from the joint between theinoving buckets 3 and block 10, I 'provide a guard plate 13 in-x terose-d b'etween the block 10 and the 'base of he iixednozzle 9. A secondguard plate 15 may be used to prevent escape of fluid from the nozzles 7around the top of the row of buckets 7 By the construction described itwill be seen that the elastic fluid, in traversin the turbine andpassing successively throng nozzles and moving buckets, will expand andincrease or fan outward circumferentially in the direction of theexhaust. After issuing from the last row of moving enter the opening 11and pass through the nozzles 7 Without losing its velocityor form,

ing eddies, or. otheivviseundergoing losses. O n the contrary, theelastic fluid will freely issue from the row of moving buckets 3 into'the next nozzles 7 without appreciable loss. In connection with theopening 11, I prgi vide a valve 14. This valve is shown mounted in waysin the diaphragm 6,' although it maybe carried in any other manner. Itisadapted to be slid to expose or open up a certain peripheral extent ofbuckets 7. The valve is so arranged that as it is opened, the be in thedirection of the This is a parent from the illustration in Fig. 2, inwillich the moving buckets travel in the direction of the arrow, andtheir discharge is inV the op osite direction. As the valve 14 is thenozzles 7, adjacent to the wall 12, will be the iirst ones exposed. VIprefer to provide one of tliese sliding valves 14 for each diaphragm. Inthe first diaphragm orhead of the shell, the ordinary separate valves,which are now used in elastic fluid turbines, may be used for cutting inor cutting out one or more separate nozzles at a time. These nozzleswhen cut out are cutout in the direction opposite to the rotation of thewheel.

.'Fig. 2 illustrates the position of the valves when theturbine isoperating under part load. The initial valves are all cut off except theone or ones which control but one or two nozzles at the initial end ofthe turbine. The valves 14-14 ,for the stages shown in the drawings arepartly closed so that but two or three ofthe nozzles 7 in eachdiaphragm. are open. The elastic fluid in traversing the turbine Will beconiined to a path ad'acent to 11. W ile it may fan out to some extentin each stage, yet when it reaches the opening 11 at the end of eachstage it will be confined to the opening disclosed by the valve 14. Atpart loads, therefore, the turbine will operate Without undue loss ofefficiency because the elastic iiuid will have a free passage throughthe entire length of the turbine and Will be the buckets 3 it will.

the edges 12 of the openings concentratediat each diaphragm iii such amanner that ",the nozzles at the diaphragm lwill be utilized to theircomplete capacity/f The invention may be applied to other forms ofelastic iiuid turbines and is not necessarily restricted to the axialflow t pe.

Insteado'i' using intermediate xed nozz es 8 andv 9, intermediatebuckets 'may' be. einloyed which serve solely for the purpose ofiverting'the {iiii'd discharged from the in oving buckets.. In thisIcase the entire'expansion will be made by the nozzles 7v on theprinciple disclosed'in my Patent No. 566,968.

' f -In accordance with the provisions of the patent statutes, Ihavedescribedthe prirr ciple of rn invention, together with theapparatus ich I now consider to represent :the best embodiment thereof',but I desire to have lit understood that the apparatus shown is merelyillustrative` and that the inventif-n can be carried out in other ways.

Havin now particularlv described the nature o my invention, an the sameis to' be performed, what l claim and desire to secure by LettersPatent, is:

1. An elastic fluid turbine having aV shell divided vby diaphragms intoseparate stages, moving and stationary buckets 'in each stage, andnozzles in the diaphragnis, there being a space between the-dischargefrom 'a inov'ing.

bucket in a-,stage to the next diapliraginand an element'having apassage in the space, the said passage connecting the discharge i'ionithe bucket to the lnext nozzle, it being sub stantially of the saineshape as the fluid jet.

2. A turbine divided into stages by diaphragms, there being an clementwith apassage between the row ci' moving bnc {ets which last dischargesiiuid in each stage and the next diaphragm, the passage increasingcircumfeientially and decreasing radially, in the direction of theexhaust.

in what marinier 3. A turbine divided into stages by diapliragins, therebeing confining walls .to carry the next nozzle, the said walls being soshaped as to conduct the iluid without substantial loss of velocity.

'i 4. A turbine divided into si ages by dia- Iphragms, there being topand bottoni con l'ning walls to carry he ilnid ii'oin the last bucket tothe next nozzle, the said ualls being so shaped as to conduct the fluiduitliout substantial loss of velocity.

5. A turbine having ina stage, adjacent to the diaphragm oi' the nextstage, the said block having a passage, receiving fluid from the,disc-.hargczof the iluid from the last bucket to the stages, with ablock" wheel within the stage, one edge being sub` an opening in thespace, With a valve ad `jacent 4to the nozzles for controlling admissionof fluid to them.

7. A stage turbine, having a space in a stage between the discharge fromthe buckets of the Wheel and the nozzles which admit to the next stage,there being an element with-5 an opening in the space, with a valve atthe ultimate end of the opening.

8. Ast-age turbine, having a space inal stage between the discharge fromthe bucketsl oi' the wheel and the nozzles which admit to the nextstage, there being an element hav'- ing a passage Within, the space, thesaid passagefincreasing circumferentially in the direction oi' theexhaust, the circumferential enlargement being made by an inclined edgeof the passage and means for varying the cross sectional area of thepassage, the said means operating to expose the nozzles in the directionopposite to the direction of rotation of the Wheel, so that the iluid atlow loads will iiow along the inclined edge of the opening.

9. A stage turbine, a space in a stage between the discharge from thebuckets of the wheel and the nozzles which admit to the next stage,`there being an elementhavin a passage Within the spacewith a slide va veat the ultimate end Vthereof, the assage increasino leircumferent'iallyin the irection of the exhaust, the circumferential enlargement beingmade by an inclined edge of theA .stage between the disehar e from thebuckets ofthe Wheel and the noz es which admit to the next stage, there.bengapassage Within the space, with a slidewalve'at the ultimate endthereof, the passage increasing circumferentially and decreasingradially in the di-l rection of the exhaust,the circumferentialenlargement being made by an inclined edge of the passage, the valvemoving to expose the nozzles-in the direction op osite to the directionof rotation of the Whee so that the iiuid at low loads will flow alongthe inclined edge of the o eningi This spec cation signed and witnessedthis 27th day of A ril, 1907.

CPHARLES G. CURTIS.

Witnesses;

JOHN L. LoTscH, M. L. HORMEL.

